Michigan Technological University’s Michigan Tech Transportation Institute (MTTI) and Michigan Tech Research Institute (MTRI), in cooperation with the Center for Automotive Research and the Michigan Department of Transportation, undertook a project for the USDOT Research and Innovative Technology Administration (RITA) that explores the use of remote sensing technologies to assess and monitor the condition of bridge infrastructure and improve the efficiency of inspection, repair, and rehabilitation efforts. The investigation built on existing work that places sensors directly on the bridge structure to assess deterioration and damage.
Remote sensing technologies were correlated with in-place sensors to obtain bridge condition assessment data without the need to place heavy instrumentation on the structure. This information was analyzed by a computer decision support system to develop unique signatures of bridge condition. Monitoring how these signatures change over time provides state and local engineers with additional information used to prioritize critical maintenance and repair of our nation’s bridges. The ability to acquire this information remotely from many bridges without the expense of a dense sensor network provides more accurate and near real-time assessments of bridge condition. Improved assessments allow for limited resources to be better allocated in repair and maintenance efforts, thereby extending the service life and safety of bridge assets, and minimizing costs of service-life extension.
April 6, 2010
Project mention: "Michigan Tech Prof Leads Team Listening to Bridges" - Great Lakes Innovation and Technology Report
April 6, 2010
Project mention: "Tech Researchers Study Bridge Health" - Daily Mining Gazette
April 5, 2010
Project mention: "Bridges in Trouble: Diagnosing their Ills from a Distance" - Michigan Tech News
April 2, 2010
About Project page updated
March 5, 2010
I-94 Overpass Closed for Emergency Repairs, to Re-open Monday, March 8 - Detroit Free Press
About the Project
Michigan Tech developed remotely sensed bridge condition signatures that can be used to enhance the effectiveness of bridge inspection teams and improve asset management programs for transportation agencies. Because no single type of sensor can provide all the information needed to assess the condition of a bridge accurately, our approach integrates in-situ field sensors, “local” remote sensing data (such as infrared thermography), and stand-off remote sensing data (such as satellite imagery) to create a unique bridge signature that provides an overall assessment of bridge structural health. These data are integrated within a decision support system (DSS) that applies information from multiple sources, including sensor data; previous inspection results; existing bridge management systems; laboratory-validated models; and meteorological inputs. The "signature" starts with a baseline index that can be used to track changes in bridge condition over time.
The system adds value by providing bridge asset managers with a tool for obtaining an assessment of bridge condition without having to instrument the bridge. And by providing inspection teams with relevant preliminary condition assessment data, bridge inspection teams can focus their efforts on trouble spots identified by the sensors as evaluated through the DSS. These indicators, combined with models and algorithms validated in the laboratory and historical bridge inspection records, provide the inputs to the DSS. The DSS allows managers and decision makers to prioritize maintenance and rehabilitation efforts based on objective data with analysis capabilities to help monitor condition, changes in condition, and plan for more cost-effective efforts.
The project had three primary goals:
- Establish remotely sensed bridge health indicators
- Develop a baseline bridge performance metric, the bridge condition signature, for benchmarking overall bridge condition
- Provide a system that enhances the ability of state and local bridge engineers to prioritize critical repair and maintenance needs for the nation’s bridges
The condition of the nation’s infrastructure has gained increased attention, primarily as a result of catastrophic events such as the I-35W collapse in Minneapolis in 2007. Deteriorating transportation infrastructure has burdened transportation agencies for many years. Bridges continue to age, and funds for the repair and replacement of this infrastructure are insufficient at current funding levels. The US is home to 600,000 highway bridges. Structural deficiency, which describes the condition of significant load-carrying elements and adequacy of waterway openings, typically relates directly to the age of a bridge (AASHTO 2008). Three percent of bridges between 15 and 19 years old, and 53 percent of those 95 to 100 years old, are structurally deficient (Memmott 2007).
In recent years, structural health monitoring (SHM) for bridges has adopted the “Level IV” approach with a primary focus of accurately monitoring in-situ behavior to assess in-service performance, detect damage, and determine condition of a structure (ISIS 2001). Most research efforts have focused on the subsystems of a structural health monitoring system including static and dynamic field testing, and both periodic monitoring and continuous monitoring, but a complete SHM system also requires routine inspection, data management, data interpretation, and decision support. Recent advances in SHM have included novel sensing technologies and assessment methods such as wireless sensors, strain sensing films and local damage identification, but a complete solution to the challenges described above has yet to be realized. SHM is further complicated by the wide degree of variability in bridge types, materials, operating environments, and structural configurations.
No single SHM method exists that is capable of completely determining the condition of a bridge. Current assessment methods provide critical information about the condition of a bridge, but the data obtained must be interpreted by a skilled professional and are typically limited to local metrics, such as stress, strain, temperature, deflection, moisture, cracking, and delamination.
Remote sensing technologies offer the ability to combine several methods to obtain a more complete assessment. These methods exhibit a divide between metrics for structural response at the global level and material distress at the local level. The combination of these metrics will provide a better picture of overall bridge condition.
The Michigan Tech team investigated the extent to which remote sensing data, particularly from sources such as aerial and satellite imagery, can be used effectively to monitor components of bridge health, such as the condition of the bridge deck or other structural elements. Stand-off remotely sensed data sources have the potential for effectively monitoring condition and quality of the road and bridge surface, if the imagery data can reliably capture indicators of current and changing condition. Because changes over a two-year period can be minimal, we used the commercial satellite archive available from vendors to determine potential changes over time, while relating condition signatures in imagery to a sample of current different high, low, and moderate quality conditions on bridges. With these methods, we were able to report on what the remotely sensed data are capable of telling transportation agency bridge assessment teams in a cost-effective and timely manner. The program achieved this assessment through a combination of controlled laboratory experiments, field demonstrations, and data analysis.
On-Site Sensor Applications
On-site sensors make non-contact measurements in close proximity to bridge structures to nondestructively sense the surface and/or interior conditions. The specific aims of the on-site sensor assessment were:
- To determine, through controlled measurements, that on-site sensors can make quantitative measurements of bridge component structural health
- To provide data to develop and demonstrate automated data processing algorithms to facilitate the cost effective use of on-site sensors by bridge inspectors and to provide quantitative structural health data to the DSS
- To provide data to determine if comparable remote sensors can make similar quantitative measurements at longer distances
Remote Sensing Applications
Satellite and airborne-based remote sensing shows increasing promise for monitoring the condition of road surface infrastructure. This project validated and applied this capability to assess and monitor the condition of the bridge elements that are critical to bridge operation.
Three commercial Synthetic Aperture Radar systems (PALSAR, RADARSAT-II, and ENVISAT) can potentially measure both bridge vibration and deflection. We determined the sensitivity requirements to make these measurements using stand-off remote sensors, and then evaluated both theoretically and experimentally, whether these existing commercial sensors can provide the required information. These SAR systems provide the required temporal synoptic coverage at affordable cost to perform a wide area bridge assessment.
Sensor Validation and Field Studies
Representative bridge component structures, such as concrete bridge decks and supports, with varying levels of damage and material contamination are used to obtain sensor data.
The sensor data is compared with the sample ground truth data to define the quantitative relationship between sensor data and various levels of bridge component damage or contamination. The data collected was also used to develop and validate data processing algorithms for the DSS.
Once the relationships between sensor signatures and structural damage were defined and the automated data processing algorithms were developed, the combined measurement/data processing system was tested at field sites identified in conjunction with MDOT that are representative of typical operational bridge inspection situations. A series of field tests were conducted to determine an initial bridge signature based on verified technologies.
Decision Support System
The Bridge Condition Decision Support System will include the ability to apply algorithms used to extract and combine relevant condition information from sensor data, compare current sensor data to historical data to establish trends, and make recommendations to ensure optimal bridge health using cost-effective maintenance and repair protocols. As part of an integrated bridge assessment, the DSS was able to take advantage of historical data from existing systems. For our study area these were the Michigan Bridge Inspection System (MBIS) and Michigan Bridge Reporting System (MBRS).
Combining data from on-site sensors, in-situ sensors, and stand-off remote sensing using appropriate statistical algorithms, the DSS integrated data to support and expand current bridge monitoring practices. The figure shows how sensors fed into the DSS.
We plan for users to be able to select particular bridges through a mapping interface, and then be able to query historical and newly sensed data, along with algorithm-based analysis results that support cost-effective bridge monitoring and maintenance. Understanding and reporting on the extent to which the DSS is producing useful and consistent measures that are timely and cost-effective for bridge assessment teams was addressed by working closely with the input of our technical advisory committee.
Technical and Economic Assessment
A technical assessment and economic evaluation was conducted as part of the project. The technical assessment evaluated the DSS tool, its technical components (such as models and algorithms), and the sensor inputs to determine how well they perform in demonstrating integrated bridge assessments that are useful for the transportation agency end-user. This included assessing the accuracy and reliability of bridge inspection measurements made by tested sensors and comparing these measures to standard measures used by bridge.
The economic evaluation examined the costs of the developed sensing techniques and evaluate these costs in relationship to the added value that the techniques supply in terms of improved bridge health monitoring. Ultimately, this task answers the question of whether the developed techniques are cost effective or not as demonstrated, with an analysis of likely future costs for full implementation.
Tasks and Deliverables
Task 1 Project Administration
January 2010–January 2012
- Deliverable 1-A: Quarterly Reports
- Deliverable 1-B: Final Report Main Body and Appendices
- Decision support system for integrating remote sensing in bridge condition assessment and preservation paper
- Measuring and Communicating Bridge Performance with Remote Sensing Technologies (TRB 2012) Presentation
- Implementation of the Digital Image Correlation Method as a Bridge Condition Assessment and Bridge Performance Measurement Tool (TRB 2012) Presentation
- Integration of Traditional and Non-Traditional Remote Sensing Bridge Condition Assessment. T. Ahlborn, D. Harris, C. Brooks, L. Sutter. 5th International Structural Health Monitoring of Intelligent Infrastructure Conference. Cancun, Mexico. December 13, 2011. Presentation
- "Assessing Bridge Condition using Remote Sensing," Pecora 18 Remote Sensing Symposium, Nov. 14-17, 2011 in Herndon, VA
- Integration of Traditional Remote Sensing into a Framework for Structural Health Monitoring. D. Harris, T. Ahlborn, L. Sutter, C. Brooks. American Concrete Institute (ACI) Fall Convention. Cincinnati, OH. October 2011.
- "Measuring and Communicating Bridge Performance with Remote-Sensing Technologies" - Transportation Research Board 2012 Conference Abstract
- Vaghefi et al. "Application of Thermal IR Imagery for Concrete Bridge Inspection" - Precast/Prestressed Concrete Institute Convention and National Bridge Conference, Salt Lake City, Utah, Oct. 22-26, 2011 Paper
- Evaluation of Commercially Available Remote Sensors for Highway Bridge Condition Assessment (2011) - Journal of Bridge Engineering
- NSBE National Convention Technical Research Exhibition Presentation (March 25, 2011)
- Michigan Bridge Conference (March 23, 2011)
- 2010 ASNT "NDE/NDT for Highways and Bridges" presentation
- 2010 ASNT "NDE/NDT for Highways and Bridges" paper
- August 2010 Bridge Conference Poster
- 2010 AASHTO T-10 Meeting at PCI Presentation
- September 14, 2010 Poster for Michigan Tech
- TRB Annual Meeting (2011) Workshop
- TRB Annual Meeting (2011) Session AFF30
- Technical Memorandum 1—Technical Advisory Council
- Technical Memorandum 2—TAC Meeting
- Technical Memorandum 3—State of the Practice Synthesis
- Technical Memorandum 2 (Revised)—Initial TAC Meeting Announcement and Confirmed Membership
- Technical Memorandum 4—State of the Practice Synthesis
- Technical Memorandum 5—Laboratory Work Plan and Specimen Fabrication
- Technical Memorandum 6—Progress-to-Date on the Sensor Evaluation
- Technical Memorandum 7—Defining the Laboratory Testing Progress
- Technical Memorandum 8—Structural Modeling Development
- Technical Memorandum 9—Commercial Sensor Evaluation Report
- Technical Memorandum 10—Development of the Decision Support System
- Technical Memorandum 11—Laboratory Study Progress
- Technical Memorandum 12—Structural Modeling
- Technical Memorandum 13—TAC Update
- Technical Memorandum 14—DSS Update
- Technical Memorandum 15—Lab Study Progress Update
- Technical Memorandum 16—Integration of Bridge Health Indicators into DSS
- Technical Memorandum 17—DSS Decision Criteria and Development of Mobile Version
- Technical Memorandum 18—Site Identification Update
- Technical Memorandum 19—Lab Progress: Structural Model Response
- Technical Memorandum 20—Field Deployment, Instrument Installation, Calibration Plan
- Technical Memorandum 21—Summary of field demonstration including sensor evaluation and update of the DSS
- Technical Memorandum 22—Technical assessment and economic valuation update
- Technical Memorandum 23—Deliverables and Final Project Outline
- Technical Memorandum 24—Update Relating Technologies and DSS to Health Indicators
- Technical Memorandum 25—Update on the Economic Valuation of Technologies and DSS
- Technical Memorandum 26—Abstracts
- Technical Memorandum 27—DSS Evaluation
Task 2 Bridge Condition Characterization
February 2010–October 2011
- Deliverable 2-A: State of the Practice Synthesis Report
- Deliverable 2-B: Laboratory Testing and Simulations Findings Report
- Deliverable 2-C: Models, simulations, and data on remote sensing response to bridge characteristics
Task 3 Commercial Sensor Evaluation
- Deliverable 3-A: Report detailing results of commercial sensor evaluation including describing which sensors can perform most efficiently on measuring high-priority bridge condition characteristics
Task 4 Decision Support System
July 2010–March 2011
- Deliverable 4-A: Demonstration Decision Support System (DSS) available to project stakeholders through a secure web portal
- Deliverable 4-B: Report summarizing the DSS including descriptions of its components, how it integrates sensed and historical data to support bridge assessment, the algorithms and models it applies, how they were developed, and how the DSS could be moved towards operational status
Task 5 Field Demonstration
- Deliverable 5-A: Report summarizing the field demonstration results of remote sensing applications for bridge condition assessment on two selected bridges
- Factsheet on the 3D Optical Bridge-evaluation System (3DOBS)
Task 6: Assessment
October 2011–January 2012
- Deliverable 6-A: Report summarizing the results of the technical assessment and evaluation
- Deliverable 6-B: Report detailing the results of the economic evaluation
Project Team and Partners
Tess Ahlborn, PhD, PI
Dr. Ahlborn is Director of the Center for Structural Durability with the Michigan Tech Transportation Institute and an Associate Professor in structural engineering in the Civil & Environmental Engineering Department at Michigan Technological University. Her professional interests lie in the areas of bridge inspection, bridge load rating, repair of bridges, and high performance concrete (HPC) materials with applications to a sustainable transportation infrastructure, specifically prestressed concrete bridges and bridge deck applications.
She has developed load rating workshops for bridge engineers and has experimental research experience in HPC behavior emphasizing fullscale laboratory and field testing of bridges. She is an active technical committee member in the Prestressed/Precast Concrete Institute and the American Concrete Institute, and she is a licensed professional engineer.
Her primary role will be project director, ensuring that project developments and results meet Michigan Tech’s internal quality standards and that sufficient resources are available for the timely completion of the project. She will also play a significant role in all tasks, especially bridge modeling and the lab and field testing tasks.
Larry Sutter, PhD
Dr. Sutter is the Director of MTTI and Director of the USDOT sponsored University Transportation Center for Materials in Sustainable Transportation Infrastructure (UTC-MiSTI). He has an extensive background in materials characterization and has conducted research on concrete pavements, the effects of deicing chemicals on concrete pavements and bridges, and using recycled and secondary materials in concrete applications. Dr. Sutter is actively involved with research through the National Cooperative Highway Research Program and brings the team expertise in material characteristics, especially material related distress in concrete bridge decks. He will contribute significantly to the project through his expertise in material characterization measures relative to concrete durability and assessment of the deterioration of transportation materials.
Devin Harris, PhD
Dr. Harris is the Donald F. and Rose Ann Tomasini Assistant Professor in structural engineering in the Civil, Environmental, and Geospatial Engineering Department at Michigan Technological University. He will be an active team member in this project directing the bridge modeling, laboratory testing and field demonstrations. His research experiences have focused primarily on innovative materials in civil infrastructure, including Ultra-High Performance Concrete (UHPC) and the Sandwich Plate System (SPS) technology. Dr. Harris is experienced in experimental testing, including live load testing and field instrumentation of bridges.
Robert Shuchman, PhD
Dr. Shuchman is Co-Director of MTRI. He is the lead remote sensing researcher and senior technical director on the Transportation Applications of Restricted Use Technology (TARUT) Study. He has 35 years of experience in applying remote sensing to solving issues, and has contributed to over 70 technical articles and presented over 80 technical papers. He has served as principal investigator on more than 50 programs dealing with SAR imaging of ocean and terrestrial features and as a SIR-B, ERS-1, and JERS-1 principle investigator. On the Environmental Task Force (later MEDEA), Dr. Shuchman explored the use of classified government systems to provide environmental and global climate change information.
Joe Burns, PhD
Dr. Burns is a Senior Research Scientist and manager of MTRI’s Sensor and Signal Processing Technologies Laboratory, which is developing new sensing and communications technologies for remote sensing, telematic, and biomedical applications. Dr. Burns has over 20 years of experience in the development, analysis and exploitation of microwave and optical remote sensing systems, and has extensive expertise in the areas of electromagnetic analysis, simulation and measurements, and signal and image processing. He has led several research programs developing innovative measurement and signal processing techniques for remote sensing applications.
Recently, Dr. Burns has worked in a variety of research areas, including biomedical signal processing with a special emphasis on sleep research applications, alternative energy and environmental metrics, as well as novel remote sensing concepts. Dr. Burns’ experience and leadership will add depth to the project team in remote sensing applications.
Colin Brooks has 15 years of experience in applying remote sensing and GIS to a variety of issues. He is manager of MTRI’s Environmental Science Lab and will lead the decision support system development as well as interface with remote sensing technologies. He has applied high-resolution remote sensing to solving transportation related issues in three on-going research projects, such as mapping wetlands and hydrologic flow near transportation corridors and creating inventories of roadway assets. He has led the development of decision support tools that can be used by Great Lakes stakeholders to analyze impacts of contaminated sediments on human health in the Great Lakes as part of the GLEAMS Center project. He has a Master’s of Environmental Management degree from with a focus on resource ecology (1993) and a Bachelor of Science degree in Pre-Forestry (1992) that included a thesis on rapid remote sensing of coastal land cover.
Richard Wallace, M.S., is a Senior Project Manager with CAR. He serves as the project manager for CAR’s vehicle-infrastructure integration efforts with the Michigan Department of Transportation and plays a leading role in CAR’s work on current projects involving technology for transportation infrastructure monitoring. He will take a lead role in the technical evaluation and economic assessment tasks, as well as liaison with MDOT. Prior to rejoining CAR in April 2007, Mr. Wallace held the position of Research Scientist with the Michigan Tech Research Institute (MTRI). At MTRI, Mr. Wallace served as one of the lead scientists for MTRI’s “Transportation Applications of Restricted Use Technology Study” and led two of the four pilot studies that MTRI implemented in cooperation with the Michigan Department of Transportation, including those associated with traffic queues and delay and estimation of AADT with remote sensing.
Technical Advisory Committee
Deliverable 1-A: Quarterly Reports
- Quarter 1
- Quarter 2
- Quarter 3
- Quarter 4
- Quarter 5
- Quarter 6
- Quarter 7
- Quarter 8
- Quarter 9
- Quarter 10
Members and Affiliations
- Steve Cook, Michigan Department of Transportation (MDOT)
- Douglas Couto, Transportation Research Board (TRB)
- Michael Johnson, CALTrans
- Dan Johnston, Independent Materials Consultant
- Dennis Kolar, The Road Commission for Oakland County
- Duane Otter, Transportation Technology Center, Inc.
- Keith Ramsey, Texas Department of Transportation
- Carin Roberts-Wollmann, Virginia Tech
- Roger Surdahl, Federal Highways Administration (FHWA)
- Peter Sweatman, University of Michigan Transportation Research Institute (UMTRI)
- Amy Trahey, Great Lakes Engineering Group
- National Consortia on Remote Sensing in Transportation (NCRST)
- TRB Subcommittee on Sensing Technologies for Transportation Applications
Other NCRST Programs
- Environment and Planning—Mississippi State University
- Freight: Border Crossings—Ohio State University
- Freight: Congestion Pricing—Rensselaer Polytechnic Institute
- Freight: Metropolitan Ports—University of California at Santa Barbara
- Infrastructure: Bridges—University of North Carolina at Charlotte
- Infrastructure: Pavement—Western Research Institute
- Infrastructure: Rural Roads—South Dakota State University